As the Olympics play out in London, there's at least one Baltimorean dreaming about Charm City hosting the world-class athletic event - with the successors to Baltimore's swimming stars Michael Phelps and Allison Schmitt racing each other across the harbor.

That's right - the trash-strewn waterway that's now so polluted by sewage leaks and storm runoff that the health department warns people against swimming or wading in it, and says even boaters should be sure to wash their hands to avoid becoming sick.

"My hope for the future of Baltimore is to one day maybe host the Olympics - like, host the summer Olympics here, and have the swimming events in the harbor," he says towards the end of the half-hour video, which was put together largely by Living Classrooms students.

The film released earlier this summer lays out what's wrong with the harbor and what needs to be done to make it safe for people to fully enjoy the watery heart of the region. And it features some of the dedicated corps of people, young and old alike, who are striving against tall odds to make that dream a reality.

Getting the trash out of the water, fixing the sewage leaks and halting polluted runoff won't be cheap or easy. Funding is tight, and the harbor has suffered from centuries of abuse and neglect. But the Healthy Harbor campaign, launched last year, has a plan for making the harbor swimmable by the end of this decade. The question now is, will the region's leaders - and the people who elect them - care enough to demand it be carried out.

There's reason to hope things can change, the documentary shows. Dr. Ray Bahr, a passionate citizen volunteer I've profiled before, recalls on the film how a cleanup blitz in 17 East Baltimore neighborhoods reduced the torrent of trash getting into the Inner Harbor at Canton from four tons a month to one ton. That's still a lot, but it shows what can be done. Those gains are likely to be only temporary, though, unless cleanup efforts persist and people's awareness and habits change.

As the film points out, the cleanup starts on the land, not in the water. It involves residents living far inland from the harbor - all the way out beyond the Beltway, in fact, since that's where the Jones Falls and Gwynns Falls begin to flow toward the harbor.

"It's not possible to have a healthy harbor without healthy neighborhoods," says the film's narrator, Christopher Sykes, another Living Classrooms student.

It's worth remembering that Baltimore teamed up with Washington a decade ago in a bid to host the 2012 Olympics. No one was suggesting staging any swimming events in the harbor then. But who knows, maybe James Reeb's dream of swimming in the Patapsco River can become a reality by the 2020 games?